The present invention is directed to the field of combine skid plates or shoes for agricultural equipment, and is more specifically directed to a protective cover for such skid plates or shoes for preventing adhesion of soil thereto and the damage caused thereby.
Referring now to FIG. 1, there is shown a self-propelled combine 10. For purposes of illustration, a combine Model 215 manufactured by John Deere is shown. However, the invention is applicable to all makes of combines.
Referring now to FIGS. 1-3 combine 10 includes a grain head 14 for harvesting crops such as soy beans or other beans or wheat or other small grains. Grain head 14 in turn comprises a substructure (not shown), a cutterbar assembly 16 including cutter knives 18 mounted on the front of the substructure for horizontal reciprocating motion, guides or guards 20 mounted on the front of the substructure between and extending forward of cutter knives 18, and a skid plate or shoe 22 mounted on the bottom of the sub -structure rearwardly of cutter knives 18 and guards 20.
As can be seen from FIG. 2, skid plate 22 comprises multiple panels 24 of varying widths and shapes. These panels 24 are made of steel. When new, their outer surfaces are smooth and resist adhesion by the soil as combine 10 is driven forward to harvest the crops. However, as the steel begins to rust after exposure from moisture due to use in the field, the outer surfaces of panels 24 become worn and rough causing soil to adhere to them. The higher the clay content of the soil, the more the soil will adhere. As the soil adheres, it begins to accumulate in front of cutterbar assembly 16 like a plough. This soil is then fed into cutterbar assembly 16 and from there into the cleaning apparatus of combine 10 where it becomes mixed with the crops. Also, because of increased friction between skid plate 22 and the soil on crops, increased power is needed to push combine 10, thus increasing the fuel consumption of combine 10. In order to avoid these problems, the farmer has to keep stopping the combine to clean cutterbar assembly 16 and skid plate 22.
Alternatively the farmer can use combine 10 with head 14 raised above the surface of the ground. Although raising head 14 above the surface of the ground is less time consuming than stopping periodically to clean cutterbar assembly 16 and skid plate 22, it prevents combine 10 from harvesting low-lying crops. This is a particular problem with soy beans, which are harvested after the leaves fall off. The falling leaves act as a mulch, preventing the soil from drying, so that the soil adheres to skid plate 22 in great quantities. As a practical matter, combine 10 must be operated with head 14 off of the ground. This results in harvesting less than all of the crops, and in a loss of 2 to 5 bushels per acre. It is the solution of these and other problems to which the present invention is directed.